Mahdasht is one of the five cities in the Central District of Karaj County, Alborz province, Iran.
At the 2006 census, its population was 43,100 in 10,760 households, when it was in Tehran province. The latest census in 2016 counted 62,910 people in 19,147 households, by which time the county had separated from the province and become a part of recently established Alborz province.
Wikipedia https://en.wikipedia.org/wiki/Mahdasht
Coordinates 35°43'47.64" N 50°48'39.924" E